3D capture of historic costumes at Helston Museum, Cornwall

Sign reading "3D scanning project. Thanks to Cornwall Museum Partnership with funding from Arts Council England we are learning how to 3D scan our collection"In December 2017 I was asked by Helston Museum to train staff and volunteers in how to use photogrammetry to record their historic costume collection in 3D. The costume gallery had closed and become a much-needed storage area. They decided that online 3D models, and possibly through screens in the museum, would be an interesting and engaging way to present the costumes now in the museum stores. They could record and display many more than there has ever been physical gallery space for.

The best way to capture the costumes is, of course, to use a mannequin. This would allow the costume to be viewed in the way it would have been worn, and rotated and viewed from any angle, an advantage over traditional static photographs. They would use Sketchfab to display the results.

Helston Museum decided to try the project in a very public way. Training was conducted in their temporary exhibition space, with panels explaining what was going on to the public. Projectors were used to display the results, as they happened. Staff and myself were on-hand to answer any questions from the public.

Over the course of a week, I trained both permanent staff, the Director and Assistant Curator, as well as a group of volunteers. They were shown how to light the mannequins, how to photograph them for 3D photogrammetry, and how to process and clean the 3D data on one of the museum’s existing PCs.

A volunteer photographs the dressed mannequin from every angle to ensure good coverage for photogrammetry
A volunteer photographs the dressed mannequin from every angle to ensure good coverage for photogrammetry

Some volunteers were more interested in photography, others in costume handling, and others in data processing and editing. I worked with their strengths, and the museum now have a great team to take the project on themselves. I remain available for questions from the team, and hope to teach some more advanced methods as they gain experience and confidence with 3D digitisation.

Helston Museum are Cornwall’s first museum to create a Sketchfab account, where they will share the results of this ongoing project. Visit Helston Museum on Sketchfab.

 

Point Cloud Penzance – the town in 3D

Using 3D data (LiDAR) collected by the Environment Agency through the Government Open Data initiative I have created an interactive 3D model of the town centre of Penzance, Cornwall.

It’s a very detailed model, with a measurement point every 50cm or so across the entire town. There are 12.9 million vertices (points) in this model.

You may need a reasonably modern computer for the model to work correctly, but give it a try. Use your left mouse button to rotate the model, right-hand button to pan, and the scroll wheel (or equivalent gesture) to zoom.

View this model directly on Sketchfab, where you can try full-screen mode.

If you get too close to buildings you may notice that you can see the ‘points’ that the model is made from. In the future technology will allow agencies to collect much more accurate and dense data, and faster computers will allow us to view more detailed models. Until then – enjoy!

LiDAR data is extremely useful to archaeologists to identify features in the landscape. This is my primary use of such data. In the future data like this will be useful for understanding how our towns have changed. This model is presented here for a bit of fun, and to demonstrate the many uses that this kind of data can have.

Penzance LiDAR
Penzance LiDAR with Ambient Occlusion to show streets and features more clearly.

On Sketchfab and Cultural Heritage

Sketchfab screenshot

When I first started out with learning 3D visualisation techniques and software back in 2001 I longed for a way to share my models online. In the early days there was VRML and other, proprietary, methods (Superscape, Shockwave 3D, etc) but these required either big browser plugins with limited capabilities or in the case of VRML, very low polygon (simple) models. My 100,000 polygon reconstruction of the Tudor palace at Oatlands which I built from archaeological and contemporary visual evidence was never going to make it online back then.

Without providing a history of the technology used to present 3D models online – I’ve probably tried most methods through the years – we now have a splendid service called Sketchfab. I’m certain that someone has used the YouTube analogy here. Putting video online used to be hard until YouTube and the many similar services that came and went. Now you can open a Sketchfab account, upload your models, edit how you’d like them to initially appear, and share your links or embed them in your website or social media timeline. There are many sophisticated tools to change how your model appears, from its textures, to the environment and lighting, background photo, visual effects, and interactive annotations.

In the world of cultural heritage Sketchfab opens up a whole range of possibilities. Annotations allow numbered points to be attached to geometry and through the use of Markdown, those annotations can include embedded photos and hyperlinks.

Here we see a model of Hoa Hakananai’a from the British Museum’s Sketchfab account (3D capture by my colleagues at Archaeovision) with annotations to explain some of the carvings on the statue.

I’m currently working on an interactive plan of a shipwreck where annotations contain links and are used as the launch to pages with further information. It’s a really nice way to explore it without, or indeed before, any diving.

Sketchfab also contains a really good user community, including a dedicated cultural heritage group.

There’s always room for improvement. I’d love to see a point-to-point measuring tool, and I hope that the download facility one day allows for charging for models – that way people who can’t afford to give away their content can perhaps earn a bit of income, which could be good for freelancers and for Sketchfab via a commission model.

Other than that, Sketchfab is pretty amazing. Go and sign up – it’s free.

Here’s a lovely statue-menhir from the island of St Martins on the Isles of Scilly that I scanned in 2015. Sketchfab’s now ubiquity allows models to be embedded within WordPress by just pasting the link into a new line in the editor. Very handy.

 

Interactive 3D Models on Sketchfab

Publishing 3D models online used to be a pain. It always relied upon plugins, and the results could never be very detailed. Sketchfab has changed all of that, and made publishing beautifully detailed 3D models a breeze. You could use the analogy that Sketchfab is a kind of YouTube for 3D models. It is also a social network in that favourites, comments and forum discussions are all part of the system.

Whenever I can I will be publishing my models on Sketchfab, and when it’s not work in progress or for a client, I intend to enable downloads under a Creative Commons (CC BY 4.0) license.

Here’s a taster of Penzance Market Cross with a detail enhancement filter applied to it (think inverted chalk rubbing). You may need a fast broadband connection and fairly recent computer to have a smooth viewing experience of this model.

[sketchfab id=”6760debf8f17424c8f20579b910f4c2e” start=”0″ spin=”” controls=”1″]

 

Recording St Piran’s Oratory – 3D model and animation

I have now completed my recent work on St Piran’s Oratory on behalf of St Piran Trust and Cornwall Archaeological Unit. It was a challenging task requiring a huge amount of computer resources and time, with colleagues at Archaeovision helping when my computer broke down, but I am pleased with the results.

Here is a short animation of St Piran’s Oratory, digitally freed from its concrete walls:

Here is an interactive model which you can zoom, turn, and inspect:

[sketchfab id=”f2f60441723f433cb230153768cf5f77″ start=”0″ spin=”” controls=”1″]

And here is an interactive 3D model of the complete Oratory structure with the concrete walls we see today:

[sketchfab id=”b360da3fe0ca4deda9d6d8b03e2cb4cf” start=”0″ spin=”” controls=”1″]

We must now wait for the final report by CAU (to which this data contributes) to better understand the building and its phasing. Watch this space.

Recent 3D Scanning in West Cornwall

Noti Noti stone

A few weeks ago I gave a talk to the Cornwall Archaeological Society about 3D capture methods in archaeology, with examples of some of my recent work. It’s all work in progress, but here are some of the images shown during the lecture.

The stones were all chosen as case studies as they all contain details which can be difficult to see with the naked eye under normal lighting conditions. They include the Noti Noti stone in St Hilary, an inscribed stone and decorated crosses at Phillack, the Penzance Market Cross (left elevation) and the Cunaide Stone in Hayle.

Reprocessing the St John the Evangelist data from Gulval

Since first posting about the images of the Four Evangelists found on the medieval cross-base at Gulval Church, I have been striving to produce clearer images of each saint for inclusion in a publication. The image will only ever be as good as the condition of the stone allows, but it is possible to wring a fair amount of detail from the monument through digital means.

The most difficult image of the Evangelists on the Gulval stone is St John. Depicted as half man, half eagle, his side of the cross base is damaged and worn, especially at the top. The details which I would like to further enhance are the eagle head, and the book he is holding in his hand. This is the only side where the lettering is far from clear, and many people remain to be convinced that there is indeed an “IH” (Iohan) carved on it at all.

As many archaeologists do, I have become rather obsessed with this image. When processing data of this nature one does have to be very careful in the interpretation, and not see what one wants to see. Part of my ‘therapy’, if you like, is to blog about the results as I go.

So, I have re-processed the photographs of the east side of the cross-base using the highest level of detail that my computers will allow, adding in some extra angles which I did not use in my initial images, to try and capture further detail at the sculpture’s head level. The processing took from about 7am until 6pm. After some tidying of the data (and a fair amount of quiet wishing that the computer wouldn’t crash), I produced a 1.7GB point cloud ready to inspect.

The use of false colour can be really useful, as it affects one’s perceptions of the data. Good for ‘getting your eye in’ to the data, and the shapes of the carving.

So without further ado, here are some renderings of St John with his Symbol’s head (the eagle). Can you spot any vertical lettering on his book? Fellow digital specialists please note that this is still rough data!

gulval2-east-ambient-occ-1024-128s-bw-hicontrast-ortho-high
High contrast ambient occlusion.
gulval2-east-ambient-occ-1024-128s-ortho-high
Greyscale ambient occlusion.
gulval2-east-ambient-occ-1024-128s-red-yellow-ortho-high
Ambient occlusion using red and yellow colouring
gulval2-east-ambient-occ-1024-128s-redwhite-ortho-high
Ambient occlusion using red and white colouring.

 

Google SketchUp 7, 3D export, and Vue 7 Infinite

[Update March 2010] In an update to Sketchup 7, you can now just go to File > Export > 3D Model and choose ‘COLLADA File (*.dae)’ as an option. This post remains as the information about extracting a KMZ file could be useful to some.

Google have just announced the release of SketchUp 7. SketchUp is a wonderfully simple 3D modelling package, often used to populate Google Earth with 3D models of famous buildings. SketchUp Pro is the paid-for ‘grown up’ version of SketchUp, allowing, amongst a range of features, 3D export of models in a variety of formats.

The free version of SketchUp only allows models to be saved in the proprietary .skp file format, and export to kml for inclusion in Google Earth. However, I noticed on the version comparison (Why go Pro) page, that listed in the 2D export feature list, that Collada (a 3D interchange format) export was supported. It’s strange to see it listed as a 2D file format, but there you go. This is exciting, as it means that the free version of SketchUp would be more usable to me (I can’t afford the $499 for the Pro version).

Sketchup Collada export

So, I downloaded SketchUp, and made a quick box model. I can do more complex models, honest!

Simple model in Sketchup 7

The next step would be to export as Collada. Since it was listed as a 2D export format, I looked for it in the 2D export menu, but JPG, PNG and TIFF were the only options. So I checked the 3D export menu, which only listed KML and a tempting link to upgrade to Pro. The help menu didn’t seem to mention Collada export either. Initially, I put this down to an error by Google, and that this was indeed a Pro feature that had slipped into the free version’s feature list.

However, rarely one to give up, I decided to export the model as KML and see what I could do with it. I noticed that KML exports were KMZ files (a compressed file containing geometry and textures). On my Mac, I convinced Stuffit 10 to unzip the KMZ file to my desktop.

unzipped KMZ file

Stuffit created a directory containing the unzipped files. At first this just looked like it was a kml file and materials, but a quick look in the ‘models’ directory revealed a file with the extension .dae – which is the extension used by Collada files. So, through a rather backdoor method, it does indeed export Collada files. Which also means that Google Earth will read Collada files, which could lead to some interesting possibilities.

The next step is to test the exported file. I’m lucky enough to have a copy of E-On Software‘s Vue 7 Infinite at work, which supports the import of Collada files. Windows users of Vue are lucky enough to have a native .skp import, but it’s something us Mac users have to go without. Collada export neatly solves this problem.

The exported file in Vue

It wasn’t that straightforward in Vue, however. The imported Collada file appeared to have no texture applied to it. A look in Vue’s material inspector revealed that for some reason the material had 100% transparency. Setting this back to 0% transparency showed my SketchUp-designed object, which I was able to render. Success!

While SketchUp Pro offers a lot more functionality, as well as plugins, the free version is still very useful for simple modelling tasks. Being able to export in 3D from the free version is a definite boon, and my use of Sketchup will definitely increase as a result.

I hope that this is of use to 3D artists out there – feel free to leave comments if you have any ideas on how to streamline the process.